In the Spline Model editor room you can add bevels to objects. Not yet available in the wertex editor or the assemble room. To do a boolean subtraction, you need to set the Quality setting of the object VERY high in the modelling room. Then in the Assembly room, chose both items and select EDIT>3D Boolean. This will bring up a dialog box that will allow for doing the subtraction. Choose the option thats right for your situation. In the capture you'll notice I subrtacted a sphere from a cube, then a cube from a sphere. Both primitives were identical before the boolean subtraction was applied. Please note: give each item a seperate name. (Not just the default 'Vertex Object.' Carrara uses this name to define which object to subtract from which. Hope this helps! Happy rendering!